Rotax 912 Voltage regulator

[HighWing]

Never a failure - 900 hours first kitfox 100 hours on second. As others, mounted aft of the firewall and often ran with strobes and incandescent position lights. I remember the caution about switching off the master before engine shut down being a no no. Apparently having the stator input without having a load can fry the unit - at least.my understanding.

[kitfox2009]

Original one lasted over 400 hours then would not control charge rate accurately. Had to run lights at times to prevent over charge. Replacement over 200 hours with no problem.
My TinyTach died after 200 hours. Is this normal? I guess we shouldn`t expect much for $50!
We are having fun practicing for our November 11 Flypast. 6 aircraft from an RV 8, 3 Cessnas, my Vixen and a Maranda. Quite the performance variation!!

Let`s all honour our Vets and fallen Servicemen/women this week.

Cheers
Don

[DesertFox4]

I've had at least 5 fail.

Some talk of the ease of overloading these enemic little units by operating too many power consuming devices while engine rpm's are too low as during taxi times, warm up times and anytime the rpms's are below 3500 or so.
I certainly have done all those things. Will change my practices and see if life expectancy increases.
I would turn on strobes and wig-wags on the ground before take off. We think this is detrimental to the regulator. I'll now wait until
take off roll to activate high load devices like strobes and try to remember to shut them off right after landing. My strobes are not LED by the way but the new project will be. That will help unload the regulator during strobe use.

The failures would manifest in early stages as temporary over voltages on the bus bar during cruise rpm's. Sometimes they would climb to 16 volts. I would flip on all electrical devices to pull the voltage down to normal range. After a while that would not help and the unit would have to be replaced.
I hear that the Van's RV 12 guys direct cooling air on to their reg/rectifiers to keep them cool.

[Dave S]

A couple points I was not aware of - Lowell about not shutting down the master before shutting down the engine ( I do have an avionics switch to shut off the radios though) and DF 4 about the load at low RPMs.

A person can learn stuff all the time on this forum

Maybe I have survived both by default rather than design as I have always shut of the engine before the master for other reasons; and, our KF has a minimal load on the rather wimpy standard Rotax alternator due to the fact that we have the auxillary belt drive alternator which takes all the high draw stuff like lights, etc while the wimpy one is just for stuff like the radio. The dual system provides that a person can isolate a bad alternator/regulator, cross tie the load and still be operational.

I almost hate to say it lest I invite murphy's ghost to visit upon me...but - never had a Rotax regulator failure over 7 years, to answer the question at hand.

Dave S
KF 7 Trigear
912ULS Warp Drive

St Paul, MN

[jiott]

I just replaced a failed one at 300 hours; it quit charging the battery. All my strobes and nav lights are LED. It is mounted in the cockpit area behind my panel. When I put the new one in, I cut a small (about1/4" square) hole in my scat tubing for the panel air vents to direct outside air toward the regulator.

[jiott]

I have heard that many guys carry a spare with them because these things can easily strand you somewhere. Almost none of the major airport maintenance shops keep these regulators in stock, so you would end up waiting several days while you have Lockwood, CPS, or Kitfox (bless them, they keep some in stock) ship one to your location.

I believe these Ducati regulators are by far the weakest link in the whole otherwise reliable 912 engine series. I wish Rotax would step up to the plate and recognize this and develop a good one of their own, or partner with another vendor, to solve this problem once and for all before they spend any more effort in developing and improving the engine itself. It only makes good business logic to attack the weakest links first. Sorry about my soapbox!

[kmach]

I have over 650 hrs with no failure, 912 uls internal generator only. regulator mounted in the cockpit.

I never shutoff the master with the engine running. If memory serves me right, the 912 operators manual covers that.

I run a fairly high load , efis ,ems, gps, radio ,transponder ,intercom, IFA electric prop, stabilizer electric trim, aeroled's aerosun wig wag and position/strobes, heater fan, aux fuel pump . Thankfully allot listed are intermittent short period use. The IFA prop , radio transmitting and trim adjustment on an idling final definitely suck the power.

[jrevens]

Thought I'd add a little info to this old thread, FWIW. These are available through Amazon -

https://www.amazon.com/DB-Electrical...96602&sr=8-295

I've been told that they are equivalent to the Ducati units used by Rotax, for about $100 less. Might be worth stocking one if you are using the original Ducati unit. I have a friend with a RANS S7 and 912ULS who is using one.

[Shadowrider]

Another option is B&C has developed a voltage regulator that they are planning on providing a lifetime warranty. Mike at Stol Creek aviation has more info if your interested.

[Delta Whisky]

This thread (and the other about the capacitor) made me nervous (flying without a back up regulator and no over voltage protection with the Rotax unit) and I just ordered one from B&C. All of the B&C components I've had have proven to be bullet proof. I asked about the need for the infamous capacitor and was informed that their unit doesn't need one - unless you have a bit of noise to clamp.